Last remaining exit
Before the Empire began dumping its unwanted citizens in Exile, it sealed off most of the tunnels that led the surface. One, however, remained unblocked, for use in an emergency. This fabled last remaining exit lay at the north end of the Unsettled Lands.
Many adventurers searched for the exit. Those who found it, however, were inevitably frustrated by its defenses. The path to the exit wound through the lair of Sulfras the dragon, and it was further guarded by a gauntlet of Empire traps. The gauntlet could only be passed through the use of a now-infamous four-part password, "Cro Bas Eng Kai."
The only Avernites known to make it through the exit alive were Hawthorne's Assassins, who collected pieces of the password that had been discovered by Erika Redmark, Patrick, Aimee, and Athron.